Ion implantation is a process used to dope impurity ions into a substrate such as, for example, a semiconductor wafer. Generally, an ion beam is directed from an ion source chamber toward a substrate. Different feed gases are supplied to the ion source chamber to obtain plasma used to form ion beams having particular dopant characteristics. For example, from the feed gasses PH3, BF3, or AsH3, various atomic and molecular ions are created within the ion source, and subsequently accelerated and mass selected. The depth of implantation of the generated ions into the substrate is based on the ion implant energy and the mass of the ions. One or more types of ion species may be implanted in the target wafer or substrate in different doses and at different energy levels to obtain desired device characteristics. A precise doping profile in the substrate is essential to proper device operation.
While implanting certain species during the implantation process, sputter from the wafer is reflected back towards the various components of the ion implantation system. Therefore, the components become heavily coated with contaminants/particles, leading to flaking. The flaking often results in elevated particle counts affecting device performance yield.